Numerical Analysis of Interfacial Failure Mechanism in Bonded Steel–Concrete Composite Connections

The formation of steel–concrete composites using individual steel and concrete elements is commonly ensured by two different connection techniques at connected interface level: mechanical connectors and structural adhesives. Among these two connection techniques, the use of structural adhesive for bonding steel and concrete elements is rapidly increasing; primarily owing to uniform transfer of stresses over the entire bonded area. The behaviour of bonded connection with change in adhesive bond layer thickness at the level of composite interface are analysed using finite element analysis under static loading to examine the ultimate strength and shear stresses. The failure governing parameters of bonded connections, such as engendered stresses in terms of von-mises and hydrostatic stresses at bearing ends of the composite interface along with changes in failure patterns (from adhesive to cohesive) are discussed. Also, the maximum engendered stresses along the failure plane for different bond layer thicknesses are examined. In case of one mm bond layer thickness the variation in shear stresses is very high along (39.28 MPa to 23.15 MPa) and perpendicular (34.62 MPa to 16.97 MPa) to the loading direction. While, the specimen with three mm thickness exhibits maximum load bearing capacity, it also has relatively smaller variation in shear stresses along (34.91 MPa to 21.72 MPa) and perpendicular (32.72 MPa to 17.20 MPa), which shows uniformity of stresses with increase in thickness. However, a further increase in the thickness of the bond layer results in reduction in the shear capacity of the specimen.